The colour of fabrics can be altered during the laundering process or during wear or use by photo fading.
During the laundering process there is a tendency for coloured fabrics to release dye into the wash solution. This is a most persistent and troublesome problem as this released dye can then be transferred onto other fabrics or other parts of the same garment. The fading of coloured fabrics by sunlight during wear and during drying is also a major problem for consumers. Sun fading of fabrics is of specific concern to consumers because the contrast between exposed and unexposed areas makes it particularly noticeable. e.g on collars, inside versus outside of garments, and on wrap around garments such as saris.
In addition consumers rely on the use of clothes to protect them from UV light. It is frequently beneficial to enhace the UV protecton given by clothes.
Surfactant containing dye transfer inhibiting compositions are disclosed in EP-A-0 587 550. The dye transfer inhibition agent is a polymer selected from polyamine N-oxide containing polymers.
EP-A-0 327 927 describes a granular detergent additive comprising water-soluble polymeric compounds based on N-vinylpyrolidone and/or N-vinylimidazole and/or N-vinyloxazolidine and cationic compounds.
Detergent compositions comprising a N-vinylimidazole N-vinylpyrolidone copolymer are disclosed in EP-A-0 635 566 and EP-A-0 635 566.
The use of certain sunscreens has already been discussed in the literature. U.S. Pat. No. 4,788,054 teaches the use of N-phenylphthalisomides as ultraviolet radiation absorbers for cotton, wool, polyester and rayon. Fabric care compositions comprising a water dispersible/water soluble copolymers which prevent photofading are disclosed in EP-A-0 523 956.
WO 95/13354 discloses detergent compositions containing the combination of certain dye transfer inhibiting polymers with certain defined hydrophilic optical brighteners which are bis-[(anilino-triazinyl) amino] stilbene sulphonic acid derivatives, (e.g. as disclosed in EP-A-728 749 and GB-A-2 313 375). However, these compositions do not produce good deposition of fluorescer on the fabric to reduce photofading.
EP-A-403 062 discloses an acidic liquid laundry bleaching additive containing a thickener which comprises an solubilized amine-type fluorescent agent and preferably an amide-type polymer.
WO 96/03369 discloses the use of butylated hydroxy toluene for the protection of surfaces from physical and chemical degradation.
There is however a persistent problem that in a detergent composition it is difficult to formulate a composition that mitigates both photofading and dye transfer of fabrics and yet increases the UV barrier of fabrics due to the incompatibility of the active agents used.
The present invention has now found that the transmission of harmful rays, dye transfer inhibition and photofading of fabric can be mitigated by the use of specific detergent compositions.